(a) Field of the Invention
The present invention relates to the field of composite aircraft and more particualrly to a Flying Multi-Purpose Aircraft Carrier (FMPAC) and method of V/STOL assisted flight of fixed wing Conventional Aircraft (CA).
(b) State of the Art
Runway dependency is causing everyday problems experienced by fixed wing CA. Thus, one of the present day tendencies in aeronautics is to provide an aircraft with V/STOL (Vertical/Short Take-OFF and Landing) capability. Such approach, however, leads to costly and less reliable aircraft configurations, having reduced maximal speed and/or payload, such as the V-22 Ospray aircraft. Various concepts of composite aircraft have been proposed to resolve the above design conflict. Configurations with low reliability, low maintainability, high production costs and low efficiency in low operation, and/or a necessity to substantially modify the CA before using it for V/STOL assisted composite flight have resulted in abandoning of numerous ideas disclosed in the prior art. Frederick et al, for example, in a British patent No. 926,613 issued on May 22, 1963, and Griffith in U.S. Pat. No. 3.070.326 issued on Dec. 25, 1962 teach a composite aircraft comprisng jet engines for a V/STOL operation. Jet engines occupy a relatively small space, but extremely large number of engines are necessary to be employed (for example, Griffiths suggests 32 engines), according to a preliminary analysis, showing that the total weight of a composite aircraft with a CA on board would be at least two times that of the lifted CA. Also, a vertical position of the gas turbine engines, which have inherent considerable length, will increase the height of the platform which will respectively increase the flight instability of the composite aircraft, especially when a CA is positioned on the top of such a platform. Further, all engines should be tiltable or a new set of horizontal engines should be employed to provide a horizontal thrust. Obviously, flight control, maintainability and reliability of a structure with such a large number of engines, introduced as a result of their inherent low impulse in static condition of work, would be poor. Further disadvantage of the Frederick's platform is that the CA, when attached to such aircraft carrier, should be positioned directly above its engines. This necessitates the provision of ductwork for the jet intakes which is both expensive and may interfere with the stability of the carried CA during separation or coupling.
Booker, also describes a composite aircraft, in a U.S. Pat. No. 3,003,717 issued on Jul. 22, 1960, wherein a large sized CA serves as a landing platform for rescuing a disabled aircraft. The disclosed aircraft has problems associated with the lack of V/STOL operation. To resolve this problem, Bennett in U.S. Pat. No. 2,843,337, issued on Jul. 15, 1958 proposes a V/STOL composite aircraft using a large helicopter blade rotor to lift a CA. Such an arrangement is, however, not efficient, from another standpoint. It reduces the lift and the stability of the CA as a result of the downwash, produced by the large diameter helicopter rotor, acting on the fixed wing aircraft before and after separation. Other patents also describe various ideas to resolve the problem associated with V/STOL of a CA. None of them, however, makes a practical sense, again, due to low reliability, low maintainability, and low efficency in operation.
Furthermore, none of the disclosed ideas in the patent literature shows a composite aircraft allowing landing of CA with a substantial margin of error. None of the prior art teaches composite aircraft for V/STOL operation comprising minimal number of gas turbine engines, so as to provide low cost manufacturing and operation of the aircraft. None of the prior art shows an aircraft with inherent stability during forward and vertical flight. None of the prior art describes a multi-purpose composite aircraft, which can be used as a "work horse" type of flying transportation vehicle, for example, to include a detachable land moving carriage, whose wheels may be locked down to the surface of the runaway platform, instead of a CA, and to carry various payloads. Such a detachable carriage, for example, may be used to carry a large volume of fire extinguishing liquids, to transport various payloads including passengers, to carry various observation or communication instruments, to transport, for example, a launcher comprising a remote piloted vehicle on-board or other flying objects, needed to be transported to the place of launching or launched during flight, and, for example, during hovering of the V/STOL composite aircraft.